Hepatitis A vaccine side effects and adverse events reported to VAERS — documenting post-approval safety monitoring data for Havrix, Vaqta, and Twinrix.
Post-licensure findings on the hepatitis A vaccines on the US childhood schedule. Source coverage of Hep A-specific post-licensure data is limited. The most significant finding is Aaron Siri's argument that the hepatitis A vaccine is associated with more deaths attributable to vaccine adverse events than the disease itself causes in comparable US populations. The system-level limitations of VAERS, VSD (Vaccine Safety Datalink), and V-SAFE apply to Hep A as they apply to all vaccines on the schedule.
Disease Burden vs. Vaccine Adverse Event Burden
Aaron Siri argues that the hepatitis A vaccine is associated with more deaths attributable to vaccine adverse events than the disease itself causes in comparable US populations.
The reasoning:
Hepatitis A in healthy children is typically mild or asymptomatic — severe illness and death from hepatitis A occur primarily in adults with underlying liver disease
Pre-vaccine US deaths from hepatitis A were fewer than 100 per year (overwhelmingly in adults)
Post-vaccine adverse event reports in VAERS for hepatitis A vaccines have included deaths and serious adverse events that, when totaled, may exceed the disease burden in the population being vaccinated (children)
This claim is structurally similar to Siri's parallel claim about hepatitis B vaccines: a vaccine targeting a disease that is mild in children may cause more harm than benefit in the vaccinated population if the vaccine has any non-trivial adverse event rate.
CDC Autism Lawsuit: Hep A Not Studied
In court stipulation responding to ICAN's lawsuit, the CDC identified its complete evidence base for claiming infant vaccines do not cause autism: 20 studies. Hepatitis A vaccines were not examined in any of the 20 studies. See Post-Licensure Safety Monitoring.
VAERS, VSD, V-SAFE Coverage
Hepatitis A vaccines are nominally subject to post-licensure surveillance through:
VAERS — passive reporting; estimated to capture <1% of actual adverse events
These surveillance systems have not generated regulatory action specific to Hep A vaccines. See the linked concept pages for documentation of why these systems have not produced reliable post-licensure safety signals.
AHRQ Comprehensive Review
The 2014 AHRQ comprehensive review of 20,478 studies found zero qualifying safety studies for most routine childhood vaccines. The hepatitis A vaccines are part of this finding. See Post-Licensure Safety Monitoring.
Does the hepatitis A vaccine cause more deaths than the disease in children?
Aaron Siri argues that the hepatitis A vaccine is associated with more deaths attributable to vaccine adverse events than the disease itself causes in comparable US populations. Hepatitis A in healthy children is typically mild or asymptomatic, with severe illness and death occurring primarily in adults with underlying liver disease. Pre-vaccine US deaths from hepatitis A were fewer than 100 per year, overwhelmingly in adults.
Has the CDC studied whether the hepatitis A vaccine causes autism?
No. In court stipulation responding to ICAN's lawsuit, the CDC identified 20 studies as its complete evidence base for claiming infant vaccines do not cause autism. Hepatitis A vaccines were not examined in any of the 20 studies. This gap is documented in the court filing and is part of a broader pattern where most childhood vaccines have never been studied for autism causation.
How effective is VAERS at catching hepatitis A vaccine side effects?
VAERS is a passive reporting system estimated to capture less than 1% of actual adverse events. Reports for hepatitis A vaccines have included deaths and serious adverse events, but because VAERS lacks denominator data and relies on voluntary reporting, the true adverse event rate cannot be calculated from VAERS data alone. The CDC has refused to implement an active reporting system that Harvard researchers built and offered.
Are there any comprehensive safety studies on the hepatitis A vaccine?
The 2014 AHRQ review examined 20,478 studies and found zero qualifying safety studies for most routine childhood vaccines — a finding that includes hepatitis A vaccines. No post-licensure surveillance system (VAERS, VSD, or V-SAFE) has generated regulatory action specific to hepatitis A vaccines. The vaccine's post-licensure safety profile effectively rests on the absence of detected signals in systems designed to miss them.
Is hepatitis A dangerous for children?
In healthy children, hepatitis A is typically mild or asymptomatic and resolves on its own. Severe illness and death occur primarily in adults with underlying liver disease. Before the vaccine was introduced, approximately 25,000-35,000 cases were reported annually in the US with fewer than 100 deaths per year — overwhelmingly in adults. These figures come from CDC epidemiological data.
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